Made available in DSpace on 2014-06-11T19:31:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-14Bitstream added on 2014-06-13T20:21:39Z : No. of bitstreams: 1 rota_mb_dr_arafcf.pdf: 1157883 bytes, checksum: 23ec64127ff9f3b94deaf756f650cf77 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / A cachaça, bebida fermento-destilada mais consumida no Brasil, tem uma produção anual estimada em 1,3 bilhão de litros, envolvendo mais de 5 mil marcas registradas e a estimativa é de que existam ainda mais de 40 mil produtores não registrados, em todo país. Para obtermos uma cachaça de boa qualidade, além dos cuidados que devem ser tomados durante seu processo de produção e o atendimento às exigências dos padrões de qualidade exigidos pela Legislação Brasileira, essa bebida deve apresentar qualidade sensorial que satisfaça ou supere as expectativas de seus consumidores. Para isso, os compostos voláteis, tais como ésteres, álcoois superiores e compostos carbonílicos, assumem papel de grande importância na caracterização do aroma e sabor característicos da cachaça. O processo de bidestilação para a obtenção da cachaça vem sendo atualmente estudado mas, com a revisão bilbiográfica, pode-se observar que o perfil aromático dessa nova bebida e da cachaça tradicionalmente obtida é geralmente determinado pelos compostos presentes maioritariamente nessas bebidas, exigidos pela Legislação Brasileira, não se conhecendo o efeito desse processo de destilação nos compostos odoríferos importantes para a qualidade sensorial dessas bebidas. Portanto, os compostos voláteis de amostras de cachaça obtidas tradicionalmente e pelo processo de bidestilação, submetidas ou não ao processo de envelhecimento, foram determinados por CG-Olfatometria, sendo encontrados 54 compostos odorantes importantes, dos quais 47 foram identificados. Essa técnica evidenciou a maior complexidade aromática das cachaças bidestiladas, pela presença, nessas amostras, de um maior número de compostos odorantes importantes, em relação às amostras tradicionais. Dentre os compostos considerados importantes para o aroma da cachaça, 12 foram destacados... / The sugar cane spirit, distilled beverage yeast-most consumed in Brazil, has an estimated annual production of 1.3 billion liters, involving more than 5000 trademark and it is estimated that there are more than 40 thousand farmers not registered in any country. To obtain a good quality of sugar cane spit, and care should be taken during their production process and meeting the requirements of the quality standards required by Brazilian law, this drink should have sensory quality that meets or exceeds the expectations of its consumers. For this, the volatile compounds such as esters, higher alcohols and carbonyl compounds, assume major role in the characterization of the aroma and flavor of sugar cane spirit. The process of bidistilled for obtaining the cachaça is currently being studied but with the bibliography review, we can observe that the flavor profile of this new beverage and sugar cane spirit traditionally obtained is generally determined mainly by compounds present in these beverages, as required by Brazilian law , not knowing that the effect distillation process in important odoriferous compounds for the sensory quality of these beverages. Therefore, the volatiles compounds of sugar cane spirit samples traditionally obtained and obtained by the bidistilled process, subjected or not to the aging process were determined by GC-Olfactometry, founded 54 important odorant compounds, 47 of which were identified. This technique showed the greater aromatic complexity of bidistilled cachaças by the presence in these samples, a greater number of important odorous compounds for traditional samples. Among the compounds considered important to the aroma of sugar cane spirit, 12 were highlighted for their contribution in defining the aromatic base of this beverage, and 10 were considered responsible for promoting the sensory differences observed among samples. The Quantitative Descriptive Analysis of cachaça samples was carried out by nine judg

Orientador: João Bosco Faria / Banca: Rubens Monti / Banca: Daniela Cardoso Umbelino Cavallini / Banca: André Ricardo Alcarde / Banca: Helena Maria André Bolini / Resumo: A cachaça, bebida fermento-destilada mais consumida no Brasil, tem uma produção anual estimada em 1,3 bilhão de litros, envolvendo mais de 5 mil marcas registradas e a estimativa é de que existam ainda mais de 40 mil produtores não registrados, em todo país. Para obtermos uma cachaça de boa qualidade, além dos cuidados que devem ser tomados durante seu processo de produção e o atendimento às exigências dos padrões de qualidade exigidos pela Legislação Brasileira, essa bebida deve apresentar qualidade sensorial que satisfaça ou supere as expectativas de seus consumidores. Para isso, os compostos voláteis, tais como ésteres, álcoois superiores e compostos carbonílicos, assumem papel de grande importância na caracterização do aroma e sabor característicos da cachaça. O processo de bidestilação para a obtenção da cachaça vem sendo atualmente estudado mas, com a revisão bilbiográfica, pode-se observar que o perfil aromático dessa nova bebida e da cachaça tradicionalmente obtida é geralmente determinado pelos compostos presentes maioritariamente nessas bebidas, exigidos pela Legislação Brasileira, não se conhecendo o efeito desse processo de destilação nos compostos odoríferos importantes para a qualidade sensorial dessas bebidas. Portanto, os compostos voláteis de amostras de cachaça obtidas tradicionalmente e pelo processo de bidestilação, submetidas ou não ao processo de envelhecimento, foram determinados por CG-Olfatometria, sendo encontrados 54 compostos odorantes importantes, dos quais 47 foram identificados. Essa técnica evidenciou a maior complexidade aromática das cachaças bidestiladas, pela presença, nessas amostras, de um maior número de compostos odorantes importantes, em relação às amostras tradicionais. Dentre os compostos considerados importantes para o aroma da cachaça, 12 foram destacados... (Resumo completo, clica acesso eletrônico abaixo) / Abstract: The sugar cane spirit, distilled beverage yeast-most consumed in Brazil, has an estimated annual production of 1.3 billion liters, involving more than 5000 trademark and it is estimated that there are more than 40 thousand farmers not registered in any country. To obtain a good quality of sugar cane spit, and care should be taken during their production process and meeting the requirements of the quality standards required by Brazilian law, this drink should have sensory quality that meets or exceeds the expectations of its consumers. For this, the volatile compounds such as esters, higher alcohols and carbonyl compounds, assume major role in the characterization of the aroma and flavor of sugar cane spirit. The process of bidistilled for obtaining the cachaça is currently being studied but with the bibliography review, we can observe that the flavor profile of this new beverage and sugar cane spirit traditionally obtained is generally determined mainly by compounds present in these beverages, as required by Brazilian law , not knowing that the effect distillation process in important odoriferous compounds for the sensory quality of these beverages. Therefore, the volatiles compounds of sugar cane spirit samples traditionally obtained and obtained by the bidistilled process, subjected or not to the aging process were determined by GC-Olfactometry, founded 54 important odorant compounds, 47 of which were identified. This technique showed the greater aromatic complexity of bidistilled cachaças by the presence in these samples, a greater number of important odorous compounds for traditional samples. Among the compounds considered important to the aroma of sugar cane spirit, 12 were highlighted for their contribution in defining the aromatic base of this beverage, and 10 were considered responsible for promoting the sensory differences observed among samples. The Quantitative Descriptive Analysis of cachaça samples was carried out by nine judg / Doutor

Thesis (Ph. D.)--Virginia Polytechnic Institute, 1956. / Typewritten. Vita. Bibliography: p. 110-114. Also available via the Internet.

Hydrophobic microporous membranes have been widely used in water and wastewater treatment by microfiltration, ultrafiltration and membrane distillation. Poly(vinylidene fluoride) (PVDF) materials are one of the most popular polymeric membrane materials because of their high mechanical strength, excellent thermal and chemical stabilities, and ease of fabrication into asymmetric hollow fiber membranes. In this work, specialty PVDF materials (Kynar 741, 761, 461, 2851, RC-10186 and RC10214) newly developed by Arkema Inc. were used to develop hollow fiber membranes via the dry/wet phase inversion. These materials were evaluated from thermodynamic and kinetic perspectives. The thermodynamic analysis was performed by measuring the cloud points of the PVDF solution systems. The experimental results showed that the thermodynamic stability of the PVDF solution system was affected by the type of polymer and the addition of additive (LiCl); and the effects of the additive (LiCl) depended on the type of polymer. The kinetic experiments were carried out by determining the solvent evaporation rate in the “dry” step and the small molecules (solvent, additive) diffusion rate in the “wet step”. Solvent evaporation in the early stage could be expressed quantitatively. In the “wet” step, the concentrations of solvent and additive had a linear relationship with respect to the square root of time (t1/2) at the early stage of polymer precipitation, indicating that the mass-transfer for solvent-nonsolvent exchange and additive LiCl leaching was diffusion controlled. The kinetic analysis also showed that the slope of this linear relationship could be used as an index to evaluate the polymer precipitation rate (solvent-nonsolvent exchange rate and LiCl leaching rate). The extrusion of hollow fiber membranes was explored, and the effects of various fabrication parameters (such as dope extrusion rate, internal coagulant flow velocity and take-up speed) on the structure and morphology of the hollow fiber membranes were also investigated. The properties of the hollow fiber membranes were characterized by gas permeation method and gas-liquid displacement method. The morphology of the hollow fibers was examined by scanning electron microscope (SEM). It was found that Kynar 741 and 2851 were the best among the PVDF polymers studied here for the fabrication of hollow fiber membranes. In order to reduce the problems associated with the hydrophobicity of PVDF on hollow fiber module assembly, such as tubesheet leaking through problem and fouling problem, amine treatment was used to modify PVDF membranes. Contact angle measurements and filtration experiments were performed. Fourier-transform infrared (FT-IR) spectroscopy and energy dispersive x-ray analysis (EDAX) were used to analyze the modified polymer. It was revealed that the hydrophilicity of the modified membrane was improved by amine treatment and conjugated C=C and C=O double bonds appeared along the polymer backbone of modified PVDF. Hollow fiber membranes fabricated from Kynar 741 were tested for water desalination by vacuum membrane distillation (VMD). An increase in temperature would increase the water productivity remarkably. Concentration polarization occurred in desalination, and its effect on VMD could be reduced by increasing the feed flowrate. The permeate pressure build-up was also investigated by experiments and parametric analysis, and the results will be important to the design of hollow fiber modules for VMD in water desalination.

Hydrophobic microporous membranes have been widely used in water and wastewater treatment by microfiltration, ultrafiltration and membrane distillation. Poly(vinylidene fluoride) (PVDF) materials are one of the most popular polymeric membrane materials because of their high mechanical strength, excellent thermal and chemical stabilities, and ease of fabrication into asymmetric hollow fiber membranes. In this work, specialty PVDF materials (Kynar 741, 761, 461, 2851, RC-10186 and RC10214) newly developed by Arkema Inc. were used to develop hollow fiber membranes via the dry/wet phase inversion. These materials were evaluated from thermodynamic and kinetic perspectives. The thermodynamic analysis was performed by measuring the cloud points of the PVDF solution systems. The experimental results showed that the thermodynamic stability of the PVDF solution system was affected by the type of polymer and the addition of additive (LiCl); and the effects of the additive (LiCl) depended on the type of polymer. The kinetic experiments were carried out by determining the solvent evaporation rate in the “dry” step and the small molecules (solvent, additive) diffusion rate in the “wet step”. Solvent evaporation in the early stage could be expressed quantitatively. In the “wet” step, the concentrations of solvent and additive had a linear relationship with respect to the square root of time (t1/2) at the early stage of polymer precipitation, indicating that the mass-transfer for solvent-nonsolvent exchange and additive LiCl leaching was diffusion controlled. The kinetic analysis also showed that the slope of this linear relationship could be used as an index to evaluate the polymer precipitation rate (solvent-nonsolvent exchange rate and LiCl leaching rate). The extrusion of hollow fiber membranes was explored, and the effects of various fabrication parameters (such as dope extrusion rate, internal coagulant flow velocity and take-up speed) on the structure and morphology of the hollow fiber membranes were also investigated. The properties of the hollow fiber membranes were characterized by gas permeation method and gas-liquid displacement method. The morphology of the hollow fibers was examined by scanning electron microscope (SEM). It was found that Kynar 741 and 2851 were the best among the PVDF polymers studied here for the fabrication of hollow fiber membranes. In order to reduce the problems associated with the hydrophobicity of PVDF on hollow fiber module assembly, such as tubesheet leaking through problem and fouling problem, amine treatment was used to modify PVDF membranes. Contact angle measurements and filtration experiments were performed. Fourier-transform infrared (FT-IR) spectroscopy and energy dispersive x-ray analysis (EDAX) were used to analyze the modified polymer. It was revealed that the hydrophilicity of the modified membrane was improved by amine treatment and conjugated C=C and C=O double bonds appeared along the polymer backbone of modified PVDF. Hollow fiber membranes fabricated from Kynar 741 were tested for water desalination by vacuum membrane distillation (VMD). An increase in temperature would increase the water productivity remarkably. Concentration polarization occurred in desalination, and its effect on VMD could be reduced by increasing the feed flowrate. The permeate pressure build-up was also investigated by experiments and parametric analysis, and the results will be important to the design of hollow fiber modules for VMD in water desalination.

Reproduction de : Thèse de doctorat : Génie chimique : Toulouse, INPT : 2006. Reproduction de : Thèse de doctorat : Génie chimique : Budapest, Université des sciences techniques et économiques : 2006. / Thèse soutenue en co-tutelle. Titre provenant de l'écran-titre. Bibliogr. 96 réf.

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First generation bioethanol generated from feedstocks is a sustainable alternative to fossil fuels, and the demand for fuel ethanol has promoted studies on the use of the grain as feedstock. This thesis describes various process designs and the economic feasibility for producing the main product ethanol and other by-products such as Biogas and DDGS (Distillers Dried Grains with Solubles) from the grain. The techno-economic analysis was performed by the data provided by Agroetanol industry, located in Norrköping, Sweden. The key target of this simulation work was to evaluate the influence of several process designs and the main production factors on the ethanol production process, in terms of energy efficiency, ethanol production cost and plant profitability. The main aim of this work was to simulate the current industrial process and to develop novel alternative retrofits by integrating new technologies and for investigating the effects on the plant profitability. In the base case, the cost sensitivity analysis was carried out on the grain buying price, ethanol and DDGS selling price. Along with the cost sensitivity analysis, the capacity sensitivity analysis was performed on the base case model to check the influence of different capacities on the plant profitability. While coming to the study of developing alternative retrofits, the three retrofits were developed on the base case process and they are as following: Retrofit 1) modifying the distillation and dehydration section of the base case retrofit (current process in Agroetanol), Retrofit 2) checking the impact of ethanol concentration on technical and economic aspects of the plant and Retrofit 3) installing the biogas digester.The modelling effort resulted in developing the base case model with an ethanol production rate of 41,985 ton/ year. The capital cost of the base case process was calculated to be at 68.85 million USD and the aspen economic analyzer calculated the product value of the ethanol and DDGS as 0.87 USD/litre and 0.37 USD/kg, respectively. Through cost sensitivity analysis results, it is identified that the ethanol selling price and the grain buying price have significant effects on the plant economy and it is confirmed that they are the main factors playing on the plant profitability in the base case model.The results of the alternative retrofits clearly demonstrate the importance of higher ethanol tolerant strains in ethanol production, which showed a less payback period compared to the base case. The payback periods of all the cases are showing the following patterns from the least to the highest: Retrofit 2 (17%) > Base case > Retrofit 3 > Retrofit 2 (4%) > Retrofit 1.Further retrofitting analysis results also suggested that using the stillage for biogas production will help in reducing the energy costs of the plant. The energy consumption of all the retrofits in ascending manner is as follows: Retrofit 3 > Retrofit 2 (17%) > Base case > Retrofit 1 > Retrofit 2 (4%). The energy usage result comparison of all the cases shows that, in third retrofit the overall energy consumption is decreased by 40% than the base case model.

No description available.

Partitioned or Dividing Wall Columns (DWC) for distillation are currently receiving a lot more / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2009.